Bianchi et al. in Eur. J. Med. Chem.--Chimica Therapeutica 16(4), 321-326 (1981) discloses benzimidazolin-2-on derivatives having anti-ulcer and anti-secretory activity.
Clark et al. in J. Med. Chem. 21(9), 965-978 (1978) discloses imidazo[4,5-b]pyridin-2-on derivatives having analgesic activity.
It is generally well known that opening of potassium (K.sup.+) channels leads to a hyperpolarization and relaxation of cells. The presently known K.sup.+ channel openers (cromakalim and pinacidil for example) exert their effect primarily via the ATP sensitive K.sup.+ channel. They have a high affinity for vascular smooth muscle cells and are thus mostly vasodilators. Recent studies indicate, however, that K.sup.+ channel openers hyperpolarizing neuronal cells also have anticonvulsive and antiischemic effects in the central nervous system (the CNS) (European Journal of Pharmacology 167, 181-183 (1989), Neuroscience Letters 115, 195-200 (1990), Neuroscience 37(1), 55-60 (1990), The Journal of Pharmacology and Experimental Therapeutics 251(1), 98-104 (1989)). Furthermore recent studies demonstrate that potassium channel openers acting on airways smooth muscle (tracheal smooth muscle) cells will have anti-asthmatic effects (Small et al., K.sup.+ -channel opening as a mechanism for relaxing airways smooth muscle in New Anti-Asthma Drugs (pp 89-94) 1988 Birkhauser Verlag Basel, and Dr. S. G. Dilly, Cromakalim/Lemakalim, experience in hypertension and nocturnal asthma in Conference Documentation, Potassium Channels '90, The Royal College of Physicians, Dec. 6-7, 1990).